• Journal of Pharmaceutical Investigation
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• 제32권3호
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• pp.209-213
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• 2002

Diltiazem inhibits calcium channels and Iεads to vascular smooth muscle rεlaxation and negative inotropic and chronotropic effects in the hεart. Diltiazem is almost completely absorbεd after oral administration, but its extent of absolute oral bioavailability is reduced because of considerable first-pass hepatic metabolism. Diltiazem is able to dilate renal vasculature and can increase the glomerular filtration rate and renal sodium excretion. The purpose of this study was to report the pharmacokinetic changes of diltiazem after oral administration of diltiazem, 20 mg/kg, in rabbits coadministered with cimetidine, 20 mg/kg and pretreated twice per day for 3 days at cimetidine dose of 20 mg/kg. The area under the plasma concentration-time curve (AUC) of diltiazem was significantly higher in rabbits pretreated with cimetidine than that in control rabbits (p<0.01), showing about 149% increased relative bioavailability. The peak plasma concentration $(C_{max})$ and elimination half-life of diltiazem were increased significantly (p<0.05) in rabbits pretreated with cimetidine compared with those in control rabbits. This findings could be due to significant reduction of elimination rate constant by pretreated with cimetidine. The effects of cimetidine on the pharmacokinetics of oral diltiazem were more considerable in rabbits pretreated with cimetidine compared with those in control rabbits. The results suggest that the dosage of diltiazem should be adjusted when the drug would be co-administerεd chronically with cimetidine in a clinical situation.

• 약학회지
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• 제44권5호
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• pp.440-447
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• 2000

Microspheres of felodipine, which is one of the calcium channel blocker using a mixture of Eudragi $t^{R}$ RL, L, E, and cellulose on the base of Eudragi $t^{R}$ RS were investigated. Cremopho $r^{R}$ was added to each preparation of polymers in order to increase the release of felodipine from microspheres. Felodipine-loaded microspheres were prepared by a solvent evaporation method, which is based on dispersion of methylene chloride containing felodipine and polymers in 0.5 w/v % polyvinyl alcohol solution. The average diameter based on the size distribution of the felodipine-loaded microspheres was observed to be ca. 40-55 ${\mu}{\textrm}{m}$. A good and smooth surface were showed in all types of the microspheres. The amount of felodipine loaded was over 90 w/w % in all types of microspheres. The dissolution profiles of felodipine from microspheres were similar with each type of polymer, and about a 60 w/w % of the total amount of felodipine loaded to microsphere was released within 7 hours. Dissolution rate of felodipine from the microsphere was increased by addition of Cremophor. After oral administration of the felodipine-loaded microspheres in PVA solution and felodipine alone in PEG solution to rats, respectively, the pharmacokinetic study revealed that the Tmax values of the microspheres were observed in the range of 0.67~l.0 hr while that of the felodipine solution was obtained 0.33 hr. In addition, the AUC of the microspheres at 0 to 7 hr was remarkably increased in comparison to that of felodipine solution. These results revealed that the microspheres based on Eudragit RS could be a good candidate for the controlled release drug delivery system for felodipine.e.e.e.

• Journal of Applied Biological Chemistry
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• 제65권4호
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• pp.349-355
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• 2022

안정화제(과인산석회, 황 및 제강슬래그) 처리가 논토양 내 비소의 생물유효도에 미치는 영향을 비교, 검증하기 위한 포트실험을 수행하였으며 비소 오염에 취약한 농경지에 활용할 수 있는 안정화제를 선발하고자 하였다. 안정화제 처리는 0.71 Mg ha^-1 (과인산석회), 0.1 Mg ha^-1 (황) 및 7.0 Mg ha^-1(제강슬래그)를 기준량으로 각각 기준량과 2배량으로 처리하였다. 벼 이앙 67일 후(유수형성기)의 과석 2배량과 황 2배량 처리구의 토양용액 중 비소의 평균 농도는 각각 96.9 및 207.2 ㎍ L^-1로 대조구(314.5 ㎍ L^-1) 및 제강슬래그 처리구(268.6-342.4 ㎍ L^-1)의 36.1-60.5% 수준으로 유의하게 낮았다. 현미의 비소 평균 농도는 대조구의 0.16 mg kg^-1에 비해 과석 2배량 처리에서 0.09 mg kg^-1으로 가장 낮았으나 유의차는 나타나지 않았으며, 본 실험 조건에서 벼 뿌리의 iron plaque 내 비소 격리는 비소의 생물유효도를 결정하는 주요 인자가 아닌 것으로 판단되었다. 안정화제 처리에 따른 벼 생육의 통계적 유의차는 관찰되지 않았으나 과석 처리구 벼의 평균 정조중은 50.0-50.4 g/pot로 대조구의 40.4 g/pot, 황 및 제강슬래그 처리구의 26.9-48.1 g/pot에 비해 높은 경향이었다. 이는 과석 처리구의 유수형성기 토양용액 중 비소의 농도가 황 및 제강슬래그 처리구의 46.8-66.4% 수준으로 유의하게 낮았음을 고려할 때 과석의 비료 효과뿐만 아니라 비소의 생물유효도 감소에 따라 벼에 대한 비소의 독성이 감소한 결과로 판단되었다. 토양용액 중 비소의 농도, 벼 생육 등을 종합적으로 고려할 때 과석 과량 처리(1.4 Mg ha^-1)에서 상대적으로 양호한 비소의 생물유효도 감소 결과를 보였다.

• Journal of Nutrition and Health
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• 제39권3호
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• pp.252-263
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• 2006

Zinc is an antioxidant trace mineral, scavenging free radicals and known to be involved in inflammatory reactions. The prevalence of atherogenic diseases such as coronary heart disease (CHD) are increasing in Korean adults of middle age and elderly. The increased cell damage from free radicals and inflammation have been implicated in etiology of CHD, and the evidence is accumulating that low zinc status is involved in the prevalence of this inflammatory atherogenic disease. However, little is known about the zinc status of Korean CHD and its relationship with dietary zinc intake and zinc bioavailabilty. In this study the serum zinc levels of male patients with CHD over 40 yrs. were compared with that of healthy adult males and its associations with dietary zinc intake and zinc bioavailabilty affecting factors were examined. Serum zinc level was measured by HANARO research reactor using neutron activation analysis (NAA) method. The overall proportion of patients with zinc deficiency, serum zinc concentrations below $74.0{\mu}g/dL$ was 32.8% compared to the 10.3% in healthy group. The average serum zinc levels were $80.7{\mu}g/dL\;and\;88.3{\mu}g/dL$ in patients and healthy group, respectively, showing significantly low zinc status in CHD patients compared to healthy group. The intake of nutrients such as energy, carbohydrate, iron, and copper of CHD patients was significantly higher compared to that of the healthy group. In addition, the intake of calcium, iron, and protein from vegetable foods was significantly higher in CHD patients than that of healthy group. The dietary zinc intake was $12.7{\pm}4.5mg$ and $11.5{\pm}6.9mg$ in CHD patients and control group, respectively, which showed no difference. The phytate intake of patients group, which is 1389.0 mg, was significantly higher than the control group which showed 1104.8 mg. However, the ratio of phytate: zinc or phytate * calcium. zinc per 1000 kcal energy intake did not show any difference between two groups. The serum zinc levels did not show any correlation with zinc or factors that affect the bioavailability of zinc. The dietary factors influencing the zinc status were not found in CHD patients.

• 한국가정과교육학회지
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• 제17권3호
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• pp.35-52
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• 2005

본 연구는 춘천지역에 살고 있는 고등학생들의 식습관과 영양소 섭취 실태를 평가하기 위하여 318명의 대상자들에게 설문조사와 24시간 회상법을 이용하여 식이조사를 하였다. 조사대상자들의 $30.8\%$는 아침식사를 자주 결식하였으며, $28.0\%$는 하루 한번 이상 자주 간식을 섭취하는 것으로 나타났다. 하루 평균 에너지 섭취량은 1740kca1이며 열량에 기여한 영양소의 비율은 탄수화물이 $61.6\%$, 단백질은 $16.0\%$, 지방은$23.1\%$였다. 칼슘과 철분의 섭취량은 부족했으며 특히 이들 영양소의 급원식품은 식물성식품에서의 섭취비율이 높아 이로 인한 체내이용율은 더 낮은 것으로 본다. 권장량의 $75\%$ 미만을 섭취한 사람들의 비율은 칼슘, 철분, 리보플라빈의 경우 모두 $68\%$이상이었다. 전체적인 식사의 질을 평가하는 지표로 쓰이는 평균적정섭취비(MAR)는 남학생이 0.79, 여학생이 0.78로 나타났다. 영양의 질적지수(INQ)는 칼슘(0.67), 철분(0.82), 리보플라빈(0.90)을 제외한 대부분 영양소들은 1이상이었다. 영양소 섭취수준이 영양권장량의 $75\%$ 미만인 경우는 영양소의 섭취가 부족함을 의미한다. 이와 같은 결과로 볼 때 춘천지역에 있는 일부 고등학생들은 많은 영양소 중에서도 특히 칼슘, 철분, 리보플라빈의 영양소를 충분히 섭취하지 않고 있음을 알수 있었다.

• 한국식품영양과학회지
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• 제30권4호
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• pp.739-746
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• 2001

본 연구는 강원도 강릉시에 위치한 중학교 2학년에 재학중인 남녀 학생 270명을 대상으로 3일간 식사기록법을 이용하여 식이섭취를 조사한 후 1일 평균 영양소 섭취량을 파악하고 다양한 방법에 의해 영양소 섭취를 기준으로 식사의 질을 평가하였다. 조사대상자들의 하루 평균 에너지 섭취는 2114$\pm$502 kcal로 남학생은 2256$\pm$608 kcal 여학생은 1961$\pm$548 kcal로 조사되었으며 열량에 기여하는 탄수화물 : 단백질: 지질의 비율은 남학생이 61.3:16.8:21.9 여학생은 61.8:16.2:22.0으로 나타났다. 단백질은 71.7 g을 섭취하는 것으로 나타났는데 그중 동물성 식품으로 45.8%를 섭취하는 것으로 조사되어 질적으로 우수함을 알수 있었다. 영양권잘양 대비 영양소별 섭취량은 단백질 인, 비타민 B$_1$나이아신, 비타민 C는 권장량을 충분히 섭취하는 것으로 나타났으나 칼슘, 철분, 비타민A, 비타민 B$_2$는 권장량에 미달되었으며 칼슘 철분은 권장량의 75% 이하였다. 특히 칼슘은 47.3%로 칼슘 결핍 현상이 우려되는 수준이었으며 모든 영양소에 남년간의 차이는 나타나지 않았다. 영양섭취량을 권장량에 대한 비율로 나타낸 NAR은 모든 영양소에서 1보다 적게 나타났다. 특히 칼슘은 0.45로 심각성을 여실히 드러냈으며 비타민A는 0.59 철분은 0.54로 낮은 값을 나타냈고 비타민 A는 남녀간에 유의한 차이를 보였다. (p<0.001). 에너지 섭취 차이를 고려한 영양의 질적지수인 INQ 값은 단백질, 인, 비타민B$_2$는 1보다 낮아 에너지 섭취가 충분하더라도 영양부족인 것으로 조사되어 대상자들의 영양결핍 현상이 우려되며 그 개선안이 시급할것으로 생각된다. 영양권장량의 75% 이상 섭취한 집단에서 INQ값은 칼슘과 비타민 B$_2$를 제외한 모든 영양소에서 1이 넘는 것으로 나타났고 권장량의 50% 미만을 섭취하는 경우는 모든 영양소에서 1 미만으로 나타났으며 특히 칼슘, 철분과 비타민 A는 매우 낮은 값을 보였다. 이상의 조사 결과일부 청소년 중학생들은 칼슘, 철분, 비타민 A 그리고 비타민 B$_2$의 섭취가 권장량에 비해 부족한 것으로 나타났고 특히 칼슘과 철분의 섭취량은 심히 낮아 청소년들의 성장과 건강에 악영향을 끼칠 것으로 보인다. 따라서 이들 영양소에 대한 식생활의 영양적인 관리가 필요하며 학생과 학부모를 대상으로 영양교육이 절실히 필요한 것으로 생각된다.

• Asian-Australasian Journal of Animal Sciences
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• 제29권8호
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• pp.1145-1151
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• 2016

This study was conducted to evaluate the relative bioavailability (RBV) of 25-hydroxycholecalciferol (25-OH-$D_3$) to cholecalciferol (vitamin $D_3$) in 1- to 21-d-old broiler chickens fed with calcium (Ca)- and phosphorus (P)-deficient diets. On the day of hatch, 450 female Ross 308 broiler chickens were assigned to nine treatments, with five replicates of ten birds each. The basal diet contained 0.50% Ca and 0.25% non-phytate phosphorus (NPP) and was not supplemented with vitamin D. Vitamin $D_3$ was fed at 0, 2.5, 5.0, 10.0, and $20.0{\mu}g/kg$, and 25-OH-$D_3$ was fed at 1.25, 2.5, 5.0, and $10.0{\mu}g/kg$. The RBV of 25-OH-$D_3$ was determined using vitamin $D_3$ as the standard source by the slope ratio method. Vitamin $D_3$ and 25-OH-$D_3$ intake was used as the independent variable for regression analysis. The linear relationships between the level of vitamin $D_3$ or 25-OH-$D_3$ and body weight gain (BWG) and the weight, length, ash weight, and the percentage of ash, Ca, and P in femur, tibia, and metatarsus of broiler chickens were observed. Using BWG as the criterion, the RBV value of 25-OH-$D_3$ to vitamin $D_3$ was 1.85. Using the mineralization of the femur, tibia, and metatarsus as criteria, the RBV of 25-OH-$D_3$ to vitamin $D_3$ ranged from 1.82 to 2.45, 1.86 to 2.52, and 1.65 to 2.05, respectively. These data indicate that 25-OH-$D_3$ is approximately 2.03 times as active as vitamin $D_3$ in promoting growth performance and bone mineralization in broiler chicken diets.

• Asian-Australasian Journal of Animal Sciences
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• 제24권7호
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• pp.940-945
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• 2011

In order to determine whether oxalate from grasses affects feed intake, blood calcium (Ca) and other blood parameters of adult sheep, two feeding trials were conducted. In Trial 1, one group of sheep received guineagrass (0.47% soluble oxalate) and another group received setaria (1.34% soluble oxalate) for 28 d. In Trial 2, one group of sheep received guineagrass while another group received the same grass treated with an oxalic acid solution (at a rate of 30 g oxalic acid/kg dry matter of hay) for 72 d. All sheep received concentrate mixtures (0.5% of body weight) throughout the experiment. In both trials, it was observed that plasma Ca concentration (11.0-11.7 mg/dl) was significantly (p<0.05) lower in sheep fed high oxalate-containing grasses than in sheep fed low oxalate-containing grasses (12.4-13.7 mg/dl). No differences (p>0.05) were observed in concentrations of magnesium, phosphorus and parathyroid hormone in plasma between the feeding of low and high oxalate-containing grasses. In addition, no differences (p>0.05) were observed in roughage dry mater (DM) intake, total DM intake or body weight of sheep. This study suggests that sheep may consume oxalate-rich forage, but Ca bioavailability may decrease with increasing oxalate levels in the ration.

• Journal of Pharmaceutical Investigation
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• 제27권1호
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• pp.57-64
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• 1997

$Amino-{\beta}-lactam$ antibiotics are absorbed by the dipeptide transporter in the small intestine. These uptakes are coupled to a proton influx. The inward proton gradient is partly induced by the $Na^+/H^+$ exchanger and calcium ion is involved in control of this antiport. Interaction between ampicillin which is one of the $Amino-{\beta}-lactam$ antibiotics and nifedipine which is one of calcium channel blocking agents was studied in rats in vivo and with rabbit jejunum mounted on the Sweetana/Grass diffusion cells in vitro. Bioavailability of ampicillin was increased significantly when nifedipine was co-administered orally in rats. There were no differences in the distribution phase and the elimination phase when ampicillin was given either alone or with nifedipine intravenously. Conditions for in vitro experiments were determined. The lift rate of $O_2/CO_2$ gas was controlled to 3 bubbles/sec and ampicillin was stable in the Kreb's buffer at pH 6.0. Absorption of ampicillin was the greatest when the completely-stripped serosal membrane was used. Transport of ampicillin from mucosal to serosal side in the rabbit jejunum was enhanced by 32% in the presence of nifedipine (p=0.059). Above results suggest that nifedipine might increase the plasma level of ampicillin via the improved absorption in the intestine rather than the reduction in the elimination or/and alteration in the distribution.

• Asian-Australasian Journal of Animal Sciences
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• 제21권10호
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• pp.1506-1515
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• 2008

Two feeding trials were conducted to assess the relative bioavailability (RBV) of methionine hydroxy analogue calcium salt (MHA-Ca) in comparison to DL-methionine (DL-Met). Male Ross 308 (1-38 days) and Cobb 500 chickens (1-42 days) were used in studies 1 and 2, respectively. Experimental diets based on wheat and soybean meal or sorghum and soybean meal were fed during three phases. In both experiments graded levels of DL-Met and MHA-Ca were supplemented to Met+Cys deficient basal diets. Additionally, in experiment 1, increasing levels of a DL-Met preparation diluted with corn starch to 65% purity (DL-Met65) were supplemented. Birds were kept in floor pens and feed and water were available ad libitum. Body weights and feed consumption were recorded at the beginning and end of the experimental periods and weight gain and feed efficacy were computed subsequently. At the end of the experiments, a number of birds were slaughtered for carcass evaluation (dressing percentage, breast meat yield). Dose response data were analysed by both ANOVA and nonlinear common plateau asymptotic regression. In both experiments birds responded significantly to increasing levels of either methionine source. However, RBV of MHA-Ca compared to DL-Met was markedly (in many cases significantly) below 84%, the value which would have been expected from MHA-Ca's chemical characteristics. Excluding some extremely low RBV figures of trial 2, RBV of MHA-Ca averaged to about 63% in relation to DL-Met. In addition, supplementation of DL-Met65 allowed confirmation of nonlinear common plateau asymptotic regression to be suitable to determine RBV.